[BioC] finding out which tags are in a bam-file

[Hubert Rehrauer]

Hi everybody

I want to load bam-files from different sources into GappedAlignments, 
but don't know which tags are actually available in the bam-File.

With scanBam this is no problem, if the tag was not in the bam it just 
puts NULL in that place. The readGappedAlignments method however fails.

Now the question: Is there a method to find out which tags are actually 
present in a bam-file?????

regards,
hubert